Perovskite thin film annealing method, annealing apparatus, and solar cell

Abstract

A perovskite thin film annealing method, an annealing apparatus, and a solar cell, relating to the technical field of perovskite solar cells. The perovskite thin film annealing apparatus comprises a light source. The light source is configured to emit a specific light beam for heating a silicon substrate of an annealing sample. The annealing sample comprises a perovskite precursor liquid film formed on the silicon substrate. The silicon substrate is heated under the radiation of the specific light beam, and the perovskite precursor liquid film is heated, so that the perovskite precursor liquid film crystallizes from a side close to the silicon substrate to a side distant from the silicon substrate. The perovskite thin film annealing apparatus uses the silicon substrate as a heat source to heat and anneal the perovskite precursor liquid film, which can improve the crystallization quality of the perovskite precursor liquid film, and improve cell efficiency and stability.

Description

Perovskite film annealing method and annealing device, solar cell

[0001] Cross-references to related publications

[0002] This disclosure claims priority to Chinese patent publication No. 202410361877.7, filed with the Patent Office of China on March 27, 2024, entitled “Perovskite thin film annealing method and annealing device, solar cell”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of perovskite solar cells, and in particular to a perovskite thin film annealing method and annealing device, and a solar cell. Background Art

[0004] Perovskite solar cells, also known as new-concept solar cells, are third-generation solar cells that utilize perovskite-type organic metal halide semiconductors as light-absorbing materials. As an emerging field in solar cell technology, perovskite solar cells, characterized by high efficiency, low cost, and a wide range of applications, have become a research focus in the global photovoltaic field.

[0005] Among them, perovskite films need to undergo a thermal annealing process after preparation, which can promote better crystallization of the grains and improve the optoelectronic properties of the film. At present, there are three common annealing processes: the first is hot plate heating annealing, but the equipment cost of this annealing method is high, making it difficult to achieve low-cost and high-speed mass production; the second is oven heating annealing. Although this method can anneal a large number of samples simultaneously, its heating efficiency is low and the crystallization quality is not high, resulting in low battery efficiency and poor stability; the third is quartz tube mid-infrared heating annealing. This method has high heating efficiency and fast heating, but it also has the problem of low battery efficiency and poor stability. Therefore, how to provide a new perovskite film annealing method to improve battery efficiency and stability is a technical problem that needs to be solved urgently.

[0006] Public content

[0007] The purpose of the present disclosure is to provide a perovskite thin film annealing method and annealing device, and a solar cell, which can use a silicon substrate as a heat source to heat and anneal a perovskite precursor liquid film, so that the perovskite precursor liquid film crystallizes from the side close to the silicon substrate to the side away from the silicon substrate, thereby improving the crystallization quality of the perovskite precursor liquid film and improving the battery efficiency and stability.

[0008] The embodiments of the present disclosure are implemented as follows:

[0009] In one aspect, the present disclosure provides a perovskite thin film annealing device, comprising a light source configured to emit a specific light beam that heats a silicon substrate of an annealed sample. The annealed sample comprises a perovskite precursor liquid film formed on the silicon substrate. The silicon substrate heats up under the radiation of the specific light beam, heating the perovskite precursor liquid film so that the perovskite precursor liquid film crystallizes from a side close to the silicon substrate to a side away from the silicon substrate. The perovskite thin film annealing device utilizes the silicon substrate as a heat source to heat and anneal the perovskite precursor liquid film, enabling the perovskite precursor liquid film to crystallize from bottom to top, thereby improving the crystallization quality of the perovskite precursor liquid film and enhancing the efficiency and stability of the battery.

[0010] Optionally, the light source is located on the side of the silicon substrate coated with the perovskite precursor liquid film, and the wavelength of the specific light beam is between 850nm and 900nm; and / or, the light source is located on the side of the silicon substrate not coated with the perovskite precursor liquid film, and the wavelength of the specific light beam is between 400nm and 900nm.

[0011] Optionally, the perovskite thin film annealing device further includes a fly-eye lens disposed between the light source and the silicon substrate, wherein the fly-eye lens is configured to homogenize and constrain the light beam emitted by the light source.

[0012] Optionally, the perovskite thin film annealing device also includes a temperature sensor and a controller; the probe of the temperature sensor is arranged on the side of the silicon substrate away from the light source, and is configured to detect the temperature of the silicon substrate and send it to the controller; the controller is configured to control the output power of the light source according to the temperature of the silicon substrate.

[0013] Optionally, the perovskite thin film annealing device also includes: a chamber configured to accommodate the above-mentioned annealing sample, and a first pipe connected to the chamber; the first pipe is configured to fill the chamber with a gas containing at least one perovskite solvent in the initial stage of annealing, so that the surface of the perovskite precursor liquid film remains wet in the initial stage; optionally, the cavity wall of the chamber is further provided with a plurality of air outlet holes in the area facing the annealing sample, and the plurality of air outlet holes are connected to the first pipe.

[0014] Optionally, a cooling channel is provided in the wall of the chamber and is configured to cool the chamber before annealing.

[0015] Optionally, the first pipeline is further provided with a first switch for controlling whether the first pipeline is turned on. The first switch is configured to turn on the first pipeline at the initial stage of annealing and turn off the first pipeline in a subsequent annealing stage after the initial stage under the control of the controller.

[0016] Optionally, the perovskite thin film annealing device further includes: a second pipe having one end connected to the chamber, and a second switch arranged on the second pipe; the second pipe is configured to fill nitrogen or dry air into the chamber in a subsequent annealing stage after the initial stage.

[0017] In other embodiments, the first pipeline may also be connected to a nitrogen or dry air source and configured to fill nitrogen or dry air into the chamber in a subsequent annealing stage after the initial stage, and the first switch is a two-input and one-output switch valve.

[0018] Optionally, the perovskite thin film annealing device further includes: a third pipe having one end connected to the chamber and a first solenoid valve connected to the third pipe; the third pipe is configured to discharge the gas in the chamber.

[0019] Optionally, the perovskite thin film annealing device also includes a fourth pipe, a vacuum pump and a second solenoid valve; one end of the fourth pipe is connected to the chamber and the other end is connected to the vacuum pump, and the second solenoid valve is connected to the fourth pipe; the vacuum pump is configured to vacuum the chamber through the fourth pipe.

[0020] Optionally, the perovskite thin film annealing device also includes: a first chamber configured to perform initial annealing on the annealing sample, and a second chamber configured to perform subsequent annealing on the annealing sample; the first chamber is provided with a first pipe connected to the first chamber, and the first pipe is configured to fill the chamber with a gas containing at least one perovskite solvent in the initial stage of annealing to keep the surface of the perovskite precursor liquid film wet; a cooling pipe configured to cool the first chamber before annealing is provided in the cavity wall of the first chamber; the second chamber is provided with a second pipe having one end connected to the second chamber; the second pipe is configured to fill the second chamber with a gas that does not contain a perovskite solvent in the subsequent annealing stage after the initial stage; the second chamber is also provided with a fourth pipe, one end of the fourth pipe is connected to the second chamber, and the other end is connected to the vacuum pump, and the vacuum pump is configured to evacuate the second chamber through the fourth pipe.

[0021] Another aspect of the present disclosure provides a perovskite thin film annealing method, which includes: using a specific light beam to radiatively heat the annealing sample so that the silicon substrate of the annealing sample is heated before the perovskite precursor liquid film, so that the perovskite precursor liquid film crystallizes from the side close to the silicon substrate to the side away from the silicon substrate, wherein the perovskite precursor liquid film is formed on the silicon substrate.

[0022] Optionally, when the specific light beam irradiates the annealed sample from the side of the silicon substrate coated with the perovskite precursor liquid film, the wavelength of the specific light beam is between 850nm and 900nm; and / or, when the specific light beam irradiates the annealed sample from the side of the silicon substrate not coated with the perovskite precursor liquid film, the wavelength of the specific light beam is between 400nm and 900nm.

[0023] Optionally, at the initial stage of annealing, a specific light beam is used to radiatively heat the annealed sample while keeping the perovskite precursor liquid film wet on the surface.

[0024] Optionally, in the initial stage of annealing, a gas containing at least one perovskite solvent is filled into the chamber of the annealing device to keep the surface of the perovskite precursor liquid film wet; in the subsequent annealing stage after the initial stage, no gas is filled into the chamber of the annealing device, or a gas containing no perovskite solvent is filled.

[0025] Optionally, the perovskite thin film annealing method further includes: before annealing and at the initial stage of annealing, cooling the chamber using a cooling pipe arranged in the chamber wall of the annealing device to keep the surface of the perovskite precursor liquid film wet at the initial stage of annealing.

[0026] Optionally, in the initial stage, the annealing temperature is between 60° C. and 200° C., and the annealing time is between 20 and 60 seconds; in the subsequent annealing stage, the annealing temperature is between 60° C. and 200° C., and the annealing time is between 8 and 20 minutes.

[0027] The beneficial effects of the present disclosure include at least:

[0028] The perovskite thin film annealing device and annealing method, as well as the solar cell provided by the present disclosure, utilize a silicon substrate to absorb a specific light beam to heat and anneal a sample. The silicon substrate first heats up under the radiation of the specific light beam, and then transfers the heat to the perovskite precursor liquid film thereon. That is, the perovskite thin film annealing device provided by the present disclosure can utilize the silicon substrate as a heat source to heat and anneal the perovskite precursor liquid film. This allows the perovskite to crystallize from the side close to the silicon substrate to the side away from the silicon substrate, thereby improving the crystallization quality of the perovskite precursor liquid film and improving the battery efficiency and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0030] FIG1 is a schematic diagram of a structure of a perovskite thin film annealing device according to an embodiment of the present disclosure;

[0031] FIG2 is a second structural schematic diagram of a perovskite thin film annealing device according to an embodiment of the present disclosure;

[0032] FIG3 is a scanning electron microscope (SEM) cross-sectional view of a perovskite film obtained by hot stage annealing;

[0033] FIG4 is a second scanning electron microscope (SEM) cross-sectional view of a perovskite film obtained by hot stage annealing;

[0034] FIG5 is one of the scanning electron microscope (SEM) cross-sectional views of a perovskite film obtained by annealing using the annealing method or annealing apparatus disclosed herein;

[0035] FIG6 is a second scanning electron microscope (SEM) cross-sectional view of a perovskite film obtained by annealing using the annealing method or annealing apparatus disclosed herein;

[0036] FIG7 is a third scanning electron microscope (SEM) cross-sectional view of a perovskite film obtained by annealing using the annealing method or annealing apparatus disclosed herein;

[0037] FIG8 provides a schematic flow diagram of a method for annealing a perovskite film;

[0038] FIG9 is a second flow chart of the perovskite film annealing method.

[0039] Icons: 10-light source; 20-silicon substrate; 21-perovskite precursor liquid film; 30-fly-eye lens; 40-temperature sensor; 60-chamber; 62-cooling pipe; 71-first pipe; 711-first switch; 72-second pipe; 721-second switch; 73-third pipe; 731-first solenoid valve; 74-fourth pipe; 741-second solenoid valve; 80-vacuum pump; 90-carrier. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all of them. Generally, the components of the embodiments of the present disclosure described and shown in the drawings herein can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the present disclosure as claimed, but merely represents selected embodiments of the present disclosure. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present disclosure without creative effort shall fall within the scope of protection of the present disclosure.

[0042] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0043] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the disclosed product is typically placed when in use. These terms are intended solely to facilitate the description of this disclosure and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. Furthermore, the terms "first," "second," "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0044] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on the specific circumstances.

[0045] Example

[0046] Referring to Figures 1 and 2, this embodiment provides a perovskite thin film annealing device, which includes a light source 10; the light source 10 is configured to emit a specific light beam that heats a silicon substrate 20 of the annealed sample. The annealed sample also includes a perovskite precursor liquid film 21 formed on the silicon substrate 20. The silicon substrate 20 heats up under the radiation of the specific light beam, and the perovskite precursor liquid film 21 is heated to cause the perovskite precursor liquid film 21 to crystallize from a side close to the silicon substrate 20 toward a side away from the silicon substrate 20. The perovskite thin film annealing device can use the silicon substrate 20 as a heat source to heat and anneal the perovskite precursor liquid film 21, promoting the crystallization of the perovskite precursor liquid film 21 from the bottom up, improving the crystallization quality of the perovskite precursor liquid film 21, and improving the battery efficiency and stability.

[0047] The perovskite thin film annealing apparatus provided herein includes a light source 10. Light source 10 is configured to emit a specific light beam, with a wavelength tailored to silicon substrate 20, to heat the sample being annealed. The light beam absorbs the specific light beam, causing the temperature of silicon substrate 20 to rise. The sample being annealed may, for example, comprise a semi-finished crystalline silicon perovskite tandem cell, and silicon substrate 20 may, for example, be a crystalline silicon subcell.

[0048] The specific light beam emitted by light source 10 irradiates silicon substrate 20, which absorbs the specific light beam and heats up. Simultaneously, as silicon substrate 20 heats up, the perovskite precursor liquid film 21 heats up due to heat conduction from silicon substrate 20. This causes heat transfer from the lower surface of perovskite precursor liquid film 21 to the upper surface, leading to nucleation and crystallization of perovskite precursor liquid film 21.

[0049] It should be noted that the upper surface of the perovskite precursor liquid film 21 is away from the silicon substrate 20, while the lower surface is close to the silicon substrate 20. The lower surface of the perovskite precursor liquid film 21 has a higher temperature and nucleates first. In other words, the bottom-up crystallization of the perovskite precursor liquid film 21 disclosed herein means that nucleation and crystallization are promoted first on the side of the perovskite precursor liquid film 21 close to the silicon substrate 20 (buried bottom interface), and then crystals grow from the bottom up.

[0050] In this embodiment, the wavelength range of the specific light beam emitted by the light source 10 needs to be determined according to the position of the light source 10 relative to the perovskite precursor liquid film 21, so it is not specifically limited. For example, as shown in Figure 1, when the light source 10 is located on the side of the silicon substrate 20 coated with the perovskite precursor liquid film 21, that is, the light source 10 is located above the perovskite precursor liquid film 21 (at this time, the perovskite precursor liquid film 21 is located between the light source 10 and the silicon substrate 20), the specific light beam emitted by the light source 10 needs to pass through the perovskite precursor liquid film 21 to reach the silicon substrate 20. The light source 10 can use a specific light beam that is absorbed by the silicon substrate 20 but is not absorbed or absorbs very little by the perovskite precursor liquid film 21, such as a near-infrared light beam. In a more specific embodiment, the wavelength of the specific light beam can be between 850nm and 900nm, without specific limitation, for example, it can be any one of 850nm, 860nm, 870nm, 880nm, 890nm and 900nm or a range value between any two of them. As shown in Figure 2, when the light source 10 is located on the side of the silicon substrate 20 that is not coated with the perovskite precursor liquid film 21, that is, the light source 10 and the perovskite precursor liquid film 21 are respectively located on both sides of the silicon substrate 20, and the light source 10 irradiates from the back of the silicon substrate 20, the light source 10 can use visible light or infrared light. At this time, there is no need to consider the absorption of the specific light beam by the perovskite precursor liquid film 21. The wavelength of the specific light beam can be between 400nm and 900nm, without specific limitation. For example, it can be any one of 400nm, 500nm, 600nm, 700nm, 800nm, 850nm and 900nm, or a range value between any two of them.

[0051] For example, in some embodiments, the light source 10 is located on the side of the silicon substrate 20 coated with the perovskite precursor liquid film 21, that is, the perovskite precursor liquid film 21 and the light source 10 are located on the same side of the silicon substrate 20, as shown in Figure 1. In this case, the light source 10 can optionally be an LED or a laser diode, and the specific light beam emitted by the light source 10 is near-infrared light, and the wavelength of the specific light beam can be between 850nm and 900nm. For example, the light beam emitted by the light source 10 can be 850nm, 870nm, or 900nm.

[0052] In this case (i.e., the light source 10 radiatively heats the silicon substrate 20 from above the perovskite precursor liquid film 21), the present disclosure uses a specific light beam with a wavelength between 850nm and 900nm to radiatively heat the silicon substrate 20. The perovskite precursor liquid film 21 does not absorb these specific light beams, but the silicon substrate 20 can absorb them. Therefore, when the light source 10 irradiates, the perovskite precursor liquid film does not absorb or absorbs very little of the specific light beam, but the silicon substrate 20 will heat up due to absorbing the energy of the specific light beam, thereby achieving a bottom-up heating of the perovskite precursor liquid film 21 through the heat conduction effect of the silicon substrate 20. In this way, the perovskite precursor liquid film 21 has a good nucleation and crystallization effect and better stability during the annealing process, thereby improving the efficiency of the battery.

[0053] At this time, the wavelength of the specific light beam emitted by the light source 10 of the present disclosure is optionally between 850nm and 900nm. In this way, it can be ensured that the specific light beam is absorbed by the silicon substrate 20 and will not be absorbed by the perovskite precursor liquid film 21. Light beams less than 850nm may be absorbed by the perovskite precursor liquid film 21, and light beams greater than 900nm may partially penetrate the silicon substrate 20, which will reduce the absorption efficiency of the silicon substrate 20. The specific light beam of 850nm to 900nm of the present disclosure can radiate and heat the silicon substrate 20 but not the perovskite precursor liquid film 21, which can ensure that the upper surface of the perovskite precursor liquid film 21 will not dry out first due to heating.

[0054] In addition, the annealing device of the present disclosure sets the light source 10 above the annealing sample, and the specific light beam passes through the perovskite precursor liquid film 21 to heat the silicon substrate 20, rather than directly heating the perovskite precursor liquid film 21. In addition to controlling the crystallization of perovskite, the reason is also to better connect with the previous coating process. The perovskite precursor liquid film 21 is formed by coating with a coating device. In the coating process, the surface to be coated of the cell faces up, and is lifted from the bottom of the silicon substrate 20 by a tray (or other transport equipment such as a manipulator) and sent to the operating position of the coating equipment. After the coating head (or liquid outlet) of the coating equipment forms the perovskite precursor liquid film 21 on the cell, it can be lifted from the bottom of the silicon substrate 20 again by the tray and sent to the annealing equipment. Therefore, by setting the light source above (the side of the silicon substrate coated with the perovskite precursor liquid film 21), space can be left below the cell (silicon substrate) for the operation of the tray or other transport equipment, which facilitates the operation connection between the coating process and the annealing process.

[0055] In other embodiments, the light source 10 is located on the side of the silicon substrate 20 that is not coated with the perovskite precursor liquid film 21, that is, the perovskite precursor liquid film 21 and the light source 10 are respectively located on either side of the silicon substrate 20, as shown in FIG2 . Optionally, the light source 10 can be a monochromatic LED, a laser diode, or a composite white light source 10; the specific light beam emitted by the light source 10 is visible light or infrared light. The wavelength of the specific light beam can be between 400nm and 900nm. For example, the central wavelength of the light beam emitted by the light source 10 can be 400nm, 500nm, 600nm, 700nm, 800nm, or 900nm, etc.

[0056] In this case (i.e., the light source 10 radiates and heats the silicon substrate 20 from the back of the cell), the present disclosure can use a specific light beam with a wavelength between 430nm and 900nm to radiate and heat the silicon substrate 20. In this way, the light beam is selected so that it will not pass through the silicon substrate 20, and this wavelength range will not cause damage to the heterogeneous crystalline silicon cell. The radiation heats the silicon substrate 20 but does not heat the perovskite precursor liquid film 21. In this way, it can also be ensured that the upper surface of the perovskite precursor liquid film 21 does not dry out first due to heating, resulting in top-down crystallization. The present disclosure achieves a bottom-up temperature increase of the perovskite precursor liquid film 21 through the heat conduction effect of the silicon substrate 20. In this way, the perovskite precursor liquid film 21 has a good nucleation and crystallization effect and better stability during the annealing process, thereby improving the efficiency of the cell.

[0057] At this time, the wavelength of the light beam emitted by the light source 10 of the present invention is optionally between 430nm and 900nm. In this way, it can be ensured that the light beam is absorbed by the silicon substrate 20 but does not pass through the silicon substrate 20. In this way, the light beam will not be absorbed by the perovskite precursor liquid film 21 (the light beam greater than 900nm will partially pass through the silicon substrate 20, thereby making the absorption efficiency of the silicon substrate 20 low; and the light beam below 430nm will damage the passivation film layer of the silicon substrate 20). Radiative heating of the silicon substrate 20 but not the perovskite precursor liquid film 21 can ensure that the upper surface of the perovskite precursor liquid film 21 will not dry out first due to heating, resulting in top-down crystallization.

[0058] Illustratively, in some other embodiments, the light source 10 may also include two groups, wherein one group of light sources 10 is located on the side of the silicon substrate 20 coated with the perovskite precursor liquid film 21, and the wavelength of the specific light beam emitted by this group of light sources is between 850nm and 900nm; the other group of light sources 10 is located on the side of the silicon substrate 20 not coated with the perovskite precursor liquid film 21, and the wavelength of the specific light beam emitted by this group of light sources is between 430nm and 900nm.

[0059] In short, the annealing apparatus of this embodiment is a combination of the upper radiant heating shown in FIG1 and the lower radiant heating shown in FIG2 . Since the light source 10 is located on the side of the silicon substrate 20 coated with the perovskite precursor liquid film 21, which is the same as the situation shown in FIG1 , and the light source 10 is located on the side of the silicon substrate 20 not coated with the perovskite precursor liquid film 21, which is the same as the situation shown in FIG2 , this disclosure will not be repeated, and reference can be made to the above description for the same details.

[0060] In this embodiment, it should be noted that the lower surface of the perovskite precursor liquid film 21 mentioned in this article refers to the side that is in contact with the silicon substrate 20, also known as the buried bottom interface, and the upper surface refers to the side of the perovskite precursor liquid film 21 away from the silicon substrate 20, opposite to the buried bottom interface.

[0061] Alternatively, the thickness of the silicon substrate 20 provided in the present disclosure can be between 90 μm and 150 μm. Since the silicon substrate 20 is very thin, the energy required for heating is relatively small. According to calculations, a 5 kW infrared LED can heat a silicon wafer (210 x 210 mm) to 120°C in 2 seconds. Therefore, the perovskite thin film annealing device disclosed in the present disclosure has a high heating efficiency, which can improve annealing efficiency.

[0062] In summary, the perovskite thin film annealing apparatus provided by the present disclosure utilizes light radiation heating, which, compared to other annealing methods, offers better uniformity and higher efficiency. Furthermore, the perovskite thin film annealing apparatus provided by the present disclosure utilizes a specific light beam radiation heating method directed at the silicon substrate to anneal the sample, thereby annealing the perovskite precursor liquid film 21. This can cause the perovskite precursor liquid film 21 to first reach nucleation conditions at the buried interface, thereby promoting bottom-up crystallization of the perovskite precursor liquid film 21.

[0063] This case innovatively utilizes the silicon substrate 20 as a heat source to heat and anneal the perovskite precursor liquid film 21, thereby improving the perovskite crystal quality and improving the battery efficiency and stability.

[0064] Figures 3-7 show a comparison of top-down and bottom-up perovskite crystallization. In SEM images, if the lower portion of the SEM cross-section shows neat crystallization and the upper portion has small fragments, those skilled in the art generally consider it bottom-up crystallization. Figures 3 and 4 show SEM cross-sectional images of top-down crystallized perovskite obtained using hot-stage annealing. Figures 5, 6, and 7 show SEM cross-sectional images of bottom-up crystallization obtained using the annealing method or annealing apparatus described herein.

[0065] Figure 3 shows crystallization from top to bottom, with broken crystals on the lower surface.

[0066] Figure 4 shows crystallization from top to bottom, and the perovskite solvent is not completely evaporated, leaving a large number of gaps at the bottom.

[0067] Figure 5 shows crystallization from bottom to top, but the aging time is insufficient and there are broken crystals on the upper surface.

[0068] Figure 6 shows crystallization from bottom to top, but the aging time is insufficient and there are broken crystals on the upper surface.

[0069] Figure 7 shows crystallization from bottom to top. The crystallization is well controlled, there is no broken crystal, and the grain boundary runs through from top to bottom.

[0070] The aging time mentioned above refers to the stage during the heating and annealing process when the solvent is evaporating but not completely. During this stage, small grains will aggregate into large grains.

[0071] In addition, it should be noted that the light source 10 may be one or more. When there are multiple light sources 10, the multiple light sources 10 may be evenly distributed on one side of the silicon substrate 20. In this way, the uniformity of the radiation heating of the silicon substrate 20 by the light beam can be improved.

[0072] Optionally, in order to further improve the uniformity of the light beam when it is irradiated on the silicon substrate 20, in this embodiment, the perovskite thin film annealing device also includes a fly-eye lens 30 arranged between the light source 10 and the silicon substrate 20. The fly-eye lens 30 is configured to homogenize and constrain the light beam emitted by the light source 10 so as to achieve a uniform light spot within a specific area (such as within the distribution range of the perovskite precursor liquid film 21).

[0073] It should be noted that the main function of the fly-eye lens 30 is to achieve light beam homogenization and confinement, so that the light beam emitted by the light source 10 can be emitted evenly after passing through the fly-eye lens 30, and the emitted light beam can illuminate the silicon substrate 20 within a specific area.

[0074] It is worth noting that if the silicon substrate 20 is fixed in the perovskite thin film annealing device during the annealing process, then the above-mentioned specific area can be roughly the same as the area of ​​the annealing sample, ensuring that the perovskite precursor liquid film 21 of the annealing sample is uniformly irradiated by the specific light beam; if the silicon substrate 20 is movable relative to the light source of the perovskite thin film annealing device, then the above-mentioned specific area can be smaller than the area of ​​the annealing sample. Through the relative movement of the annealing sample and the light source, it can be ensured that the specific light beam uniformly emitted by the light source through the fly-eye lens 30 can scan the entire perovskite precursor liquid film 21.

[0075] The perovskite thin film annealing device may also include a temperature sensor 40 and a controller; the probe of the temperature sensor 40 is arranged on the side of the silicon substrate 20 away from the light source 10, and is configured to detect the temperature of the silicon substrate 20 and send it to the controller; the controller is configured to control the output power of the light source 10 according to the temperature of the silicon substrate 20.

[0076] In this embodiment, the temperature sensor 40 may be a non-contact infrared temperature sensor 40 , so that temperature measurement can be achieved without contact.

[0077] The annealing apparatus of the present disclosure is provided with a temperature sensor 40 and a controller. Thus, the temperature sensor 40 can detect the temperature of the silicon substrate 20 in real time and provide feedback to the controller. The controller can adjust the output power of the light source 10 accordingly based on the feedback information from the temperature sensor 40, thereby maintaining the temperature of the silicon substrate 20 at a constant ideal annealing temperature. For example, the ideal annealing temperature is between 60°C and 200°C. Furthermore, the annealing temperature can optionally be between 100°C and 180°C.

[0078] In another embodiment of the present disclosure, as shown in Figures 1 and 2, the perovskite thin film annealing apparatus includes a chamber 60 configured to accommodate the annealed sample and a first pipe 71 communicating with the chamber 60. The chamber is also provided with the light source 10 and temperature sensor 40, and the controller may be disposed outside the chamber 60. The first pipe 71 is configured to fill the chamber 60 with a gas containing at least one perovskite solvent at the initial stage of annealing to maintain surface wetness of the perovskite precursor liquid film 21.

[0079] Among them, the above-mentioned keeping the surface of the perovskite precursor liquid film 21 wet means that the side (upper surface) of the perovskite precursor liquid film 21 facing away from the silicon substrate 20 remains in a liquid state and does not crystallize. The wet state can be achieved by spraying a wet gas containing a perovskite solvent, or by other means such as covering a wet object containing a perovskite solvent, or setting a wet object very close to the liquid film. The present disclosure does not impose any specific restrictions on how to keep the surface of the perovskite precursor liquid film 21 wet. The wet gas here refers to a gas containing at least one perovskite solvent, which can hinder the volatilization of the solvent on the surface of the perovskite precursor liquid film 21, so that the surface of the perovskite precursor liquid film 21 will not dry out quickly. The wet object here refers to an object containing at least one perovskite solvent, which can hinder the volatilization of the solvent in the perovskite precursor liquid film 21 by volatilizing at least one perovskite solvent, so that the perovskite precursor liquid film 21 will not dry out quickly. For example, the chamber of the finger annealing device may be filled with a humidified gas containing a perovskite solvent, such as the chamber being filled with saturated vapor of DMF (N,N-dimethylformamide).

[0080] The gas filled into the chamber 60 through the first pipe 71 at the initial stage of annealing may contain one or more perovskite solvents. The perovskite solvent content of the gas filled and the gas pressure in the chamber 60 are based on the conditions that can hinder the evaporation of the perovskite solvent and keep the surface of the perovskite precursor liquid film 21 wet without crystallization. For example, under the control of the controller, nitrogen containing DMF (N, N-dimethylformamide) is filled into the chamber 60 through the first pipe 71 at the initial stage of annealing. Optionally, the gas pressure in the chamber 60 is 1 to 3 Pa. The content of organic solvent (such as DMF) in the nitrogen is 100 ppm.

[0081] Optionally, the chamber wall facing the annealed sample may be provided with multiple vents, which are connected to the first pipe. This facilitates the uniform sinking of the gas containing the perovskite solvent onto the surface of the perovskite precursor liquid film 21, maintaining the surface wetness of the perovskite precursor liquid film and preventing the upper surface of the liquid film from reaching crystallization conditions first due to evaporation of the perovskite solvent, thereby preventing crystallization from proceeding from top to bottom.

[0082] It should be noted that the perovskite precursor liquid film 21 is kept moist only in the initial stage to prevent the upper surface of the perovskite precursor liquid film 21 (the side facing away from the silicon substrate 20) from drying out. The perovskite solvent can exist in a vaporized state or in a tiny droplet state in the gas, which is not specifically limited in this disclosure. During this initial stage, the silicon substrate is heated to promote the formation of tiny crystal nuclei at the interface (buried interface) between the liquid film and the silicon substrate.

[0083] In this embodiment, the light source 10 and the silicon substrate 20 are respectively arranged in a chamber 60. Optionally, a cooling pipe 62 is provided in the wall of the chamber 60 for cooling the chamber 60 before annealing. The chamber 60 provides a closed space for annealing, which is convenient for controlling the content of the perovskite solvent in the closed space. In the context of continuous production, the chamber temperature may be very high (such as 60°C to 200°C). After the perovskite precursor liquid film 21 enters the chamber, it will quickly become a dry film due to solvent volatilization. In this process, the solvent crystallizes from top to bottom, and the crystallization quality is not ideal. The chamber is cooled in advance by the cooling pipe in the cavity wall to ensure that the chamber temperature is basically at room temperature or lower at the beginning of annealing. Then, the silicon substrate is used to absorb the heat of the specific light beam, and then the heat is transferred to the titanium precursor liquid film attached to the silicon substrate, so that the silicon substrate interface first reaches the crystallization conditions and generates tiny crystal nuclei, thereby achieving bottom-up crystallization and improving the crystal quality. In other embodiments, the silicon substrate may further be formed with an inducing film layer that induces crystallization of the perovskite precursor liquid. For example, the surface structure of the inducing film layer may reduce the energy required for nucleation.

[0084] The cooling pipes 62 are arranged on the wall of the chamber 60. This way, the cooling pipes 62 do not affect the components inside the chamber 60 and can make the entire chamber 60 more tidy. The layout of the cooling pipes 62 is not limited by this disclosure, and the user can set it according to the structure of the chamber 60. Optionally, the cooling pipes 62 can be evenly distributed on the wall of the chamber 60, so that the temperature consistency can be maintained throughout the chamber 60.

[0085] Optionally, the first pipe 71 is further provided with a first switch 711 for controlling whether the first pipe 71 is conductive. The first switch 711 is configured to, under the control of the controller, open the first pipe 71 at the initial stage of annealing and close the first pipe 71 during the subsequent annealing stage after the initial stage. The first switch 711 may be a solenoid valve or other valve suitable for a gas pipe.

[0086] The first pipe 71 is configured to fill the chamber 60 with a gas containing at least one perovskite solvent. The present disclosure connects the first pipe 71 to the chamber 60, and a first switch 711 is provided on the first pipe 71. In this way, a gas containing at least one perovskite solvent can be introduced into the chamber 60 from the first pipe 71 in the initial stage to keep the upper surface of the perovskite precursor liquid film 21 moist during the initial annealing stage. The liquid film is heated from the bottom while maintaining the surface moist, prompting nucleation and crystallization at the bottom of the liquid film (the side close to the silicon substrate). Then, in the subsequent annealing stage, the first pipe 71 is closed, and the gas containing the perovskite solvent is no longer introduced into the chamber 60, accelerating the evaporation of the perovskite solvent and converting the perovskite precursor liquid film into perovskite crystals (perovskite dry film).

[0087] Optionally, the perovskite thin film annealing apparatus further includes a second pipe 72 having one end connected to the chamber 60 and a second switch 721 connected to the second pipe 72. The second pipe 72 is configured to fill the chamber 60 with nitrogen or dry air during the subsequent annealing phase after the initial phase. Perovskite is sensitive to moisture and oxygen in the air, and annealing in a nitrogen or dry air atmosphere can improve crystal quality.

[0088] Dry air or nitrogen is introduced into the chamber 60 through the second pipe 72, and the air pressure in the chamber 60 can also be adjusted. It should be noted that during annealing, the chamber 60 can also be maintained in a vacuum state. When the annealing is completed and the perovskite film obtained after annealing needs to be removed, the vacuum can be released by introducing dry air into the chamber 60 through the second pipe 72. When the annealing requires that the chamber 60 maintain an inert gas atmosphere, nitrogen can be introduced into the chamber 60 through the second pipe 72.

[0089] It should be noted that the first switch 711 and the second switch 721 can be a gas flow meter or a mass flow controller. A mass flow controller (MFC) not only functions as a mass flow meter, but more importantly, it can automatically control gas flow. This means the user can set the flow rate as needed, and the MFC automatically maintains the flow rate at the set value. Even if the system pressure fluctuates or the ambient temperature changes, the flow rate will not deviate from the set value. Simply put, a mass flow controller is a flow stabilization device that can be manually set or automatically controlled by a computer.

[0090] In order to facilitate the exhaust of gas in the chamber 60, optionally, the perovskite thin film annealing device can also include a third pipe 73 having one end connected to the chamber 60 and a first solenoid valve 731 connected to the third pipe 73; the third pipe 73 is configured to exhaust the gas in the chamber 60.

[0091] In order to maintain a vacuum state in the perovskite thin film annealing apparatus, the perovskite thin film annealing apparatus optionally further includes a fourth pipe 74, a vacuum pump 80, and a second solenoid valve 741. One end of the fourth pipe 74 is connected to the chamber 60, and the other end is connected to the vacuum pump 80. The second solenoid valve 741 is connected to the fourth pipe 74. The vacuum pump 80 is configured to evacuate the chamber 60 through the fourth pipe 74. In this way, by connecting one end of the fourth pipe 74 to the chamber 60 and the other end to the vacuum pump 80, the chamber 60 can be evacuated, thereby maintaining a vacuum state.

[0092] In other embodiments of the present disclosure, the perovskite thin film annealing apparatus includes: a first chamber configured to perform initial annealing on the annealed sample, and a second chamber configured to perform subsequent annealing on the annealed sample.

[0093] The first chamber is provided with a first pipe 71 in communication with the first chamber. The first pipe 71 is configured to fill the first chamber with a gas containing at least one perovskite solvent at the initial stage of annealing to keep the surface of the perovskite precursor liquid film 21 wet. A cooling pipe 62 is provided in the wall of the first chamber to cool the first chamber before annealing.

[0094] The second chamber is provided with a second pipe 72 having one end connected to the second chamber; the second pipe 72 is configured to fill the second chamber with a gas that does not contain a perovskite solvent in a subsequent annealing stage after the initial stage; the second chamber is also provided with a fourth pipe 74, one end of the fourth pipe 74 is connected to the second chamber, and the other end is connected to a vacuum pump 80, and the vacuum pump 80 is configured to evacuate the second chamber through the fourth pipe 74.

[0095] The first chamber and the second chamber are independent of each other during operation, but can be connected to each other during sample transfer. A transfer channel can exist between the first chamber and the second chamber.

[0096] It should be noted that the annealing apparatus in the present disclosure may include only one chamber, in which the entire annealing process is performed, or the annealing apparatus may include two chambers. The initial annealing stage is performed in the first chamber, and the subsequent annealing stage is performed in the second chamber. For this reason, the first conduit 71 is connected to the first chamber, and the second conduit 72 is connected to the second chamber.

[0097] The first pipeline, the second pipeline and the fourth pipeline all have the same principles as those of the above-mentioned annealing device including only one chamber, and are not described in detail here.

[0098] In addition, it should be noted that the features in this embodiment can be applied to each other as long as they are not contradictory.

[0099] The annealing device provided by the present disclosure can always maintain a gas atmosphere of at least one perovskite solvent in the first chamber, and always maintain nitrogen or dry air, or a vacuum state in the second chamber, avoiding the switching of two gas atmospheres in one chamber, and is more suitable for large-scale mass production.

[0100] In addition, another aspect of the present disclosure, as shown in FIG8 , further provides a perovskite thin film annealing method, the perovskite thin film annealing method comprising:

[0101] S100, using a specific light beam to radiantly heat the annealed sample so that the silicon substrate 20 of the annealed sample is heated before the perovskite precursor liquid film 21, so that the perovskite precursor liquid film 21 crystallizes from the side close to the silicon substrate 20 toward the side away from the silicon substrate 20, wherein the perovskite precursor liquid film 21 is formed on the silicon substrate 20.

[0102] Among them, the silicon substrate 20 of the annealed sample is radiantly heated using a specific light beam, so that the perovskite precursor liquid film 21 can be heated and increased in temperature under the heat conduction effect of the silicon substrate 20, thereby causing the perovskite precursor liquid film 21 to crystallize from the side close to the silicon substrate 20 toward the side away from the silicon substrate 20 (i.e., crystallize from bottom to top).

[0103] Optionally, the specific light beam may irradiate the annealed sample from the side of the silicon substrate 20 coated with the perovskite precursor liquid film 21 , and in this case, the wavelength of the specific light beam is between 850 nm and 900 nm.

[0104] Optionally, the specific light beam may irradiate the annealed sample from the side of the silicon substrate not coated with the perovskite precursor liquid film 21 , and the wavelength of the specific light beam is between 400 nm and 900 nm.

[0105] In other embodiments, light sources may be provided on both sides of the silicon substrate, and the wavelength of the specific light beam irradiating the annealed sample from the side of the silicon substrate 20 coated with the perovskite precursor liquid film 21 may be between 850 nm and 900 nm; the wavelength of the specific light beam irradiating the annealed sample from the side of the silicon substrate not coated with the perovskite precursor liquid film 21 may be between 400 nm and 900 nm.

[0106] In summary, the specific light beam can irradiate the annealed sample from the side of the silicon substrate 20 coated with the perovskite precursor liquid film 21, or from the side of the silicon substrate 20 not coated with the perovskite precursor liquid film 21, or from both sides of the silicon substrate 20 at the same time.

[0107] In the annealing method provided in this embodiment, a specific light beam is used to radiantly heat the annealed sample at the initial stage of annealing, while simultaneously maintaining a wet state on the surface of the perovskite precursor liquid film 21 facing away from the silicon substrate 20 (i.e., the upper surface). This prevents the perovskite precursor liquid film 21 from drying out at the initial stage of annealing, leading to top-down crystallization.

[0108] Among them, the above-mentioned keeping the surface of the perovskite precursor liquid film 21 wet means that the side (upper surface) of the perovskite precursor liquid film 21 facing away from the silicon substrate 20 remains in a liquid state and no crystallization occurs. The wet state can be achieved by spraying a wet gas containing a perovskite solvent, or by other means such as covering a wet object containing a perovskite solvent, or setting a wet object very close to the liquid film. The present disclosure does not impose specific restrictions on how to keep the surface of the perovskite precursor liquid film 21 in a wet state. The wet gas (or wet object) here refers to a gas (or object) containing at least one perovskite solvent, which can hinder the volatilization of the solvent in the perovskite precursor liquid film 21, so that the perovskite precursor liquid film 21 will not dry out quickly. For example, the chamber of the annealing equipment can be filled with a wet gas containing a perovskite solvent, such as a chamber filled with saturated vapor of DMF.

[0109] For example, at the initial stage of annealing, a gas containing at least one perovskite solvent is filled into the chamber 60 of the annealing apparatus to keep the surface of the perovskite precursor liquid film 21 away from the silicon substrate in a wet state. It should be noted that the perovskite solvent can exist in the gas in a vaporized state or in a tiny droplet state.

[0110] In this embodiment, in the subsequent annealing stage after the initial stage, no gas may be filled into the chamber 60 of the annealing device, or a gas that does not contain a perovskite solvent, such as nitrogen or dry air, may be filled into the chamber 60 of the annealing device. The specific water content of the dry air is preferably such that it does not affect the quality of the perovskite film.

[0111] For example, the step of filling the chamber 60 with gas containing at least one perovskite solvent may be specifically opening the first switch 711 on the first pipe 71 of the annealing device to 200 sccm and maintaining the vacuum at 1 Pa, so that the chamber 60 is filled with gas containing at least one perovskite solvent.

[0112] For example, the gas filled with the perovskite-free solvent may be dry air or nitrogen. For example, the second switch 721 on the second pipe 72 of the annealing device may be opened.

[0113] In addition, in this embodiment, the perovskite thin film annealing method further includes: prior to annealing and at the initial stage of annealing, cooling the chamber 60 using a cooling pipe 62 disposed within the chamber wall of the annealing device to prevent the perovskite precursor liquid film 21 from drying out quickly upon entering the chamber. For example, the chamber 60 can be cooled to below room temperature, such as 18°C ​​or 23°C (for example only).

[0114] After the chamber 60 is cooled using the cooling pipe 62 disposed within the wall of the annealing apparatus, the carrier plate 90 configured to support the silicon substrate 20 and the silicon substrate 20 coated with the perovskite precursor liquid film 21 can be placed within the chamber 60 of the annealing apparatus. A vacuum process is then performed, for example, to maintain the pressure within the chamber 60 at approximately 0.1 Pa.

[0115] Optionally, in this embodiment, in the initial stage of annealing, under the premise of keeping the perovskite precursor liquid film 21 from solidifying, the annealing temperature is between 60°C and 200°C, and the annealing time is generally at least sufficient to complete the first stage (nucleation) of crystallization, and to generate tiny crystal nuclei at or near the interface between the silicon substrate and the perovskite precursor liquid. The specific time is not limited. It is generally related to various factors affecting crystallization nucleation, such as the solvent, concentration, solution temperature, impurity type, interface orientation and morphology of the perovskite precursor liquid actually used. In specific implementation, it can be determined based on experience or multiple experiments, generally less than or equal to 30 seconds, and may also be greater than 30 seconds. In the subsequent annealing stage, the annealing temperature is between 60°C and 200°C to accelerate solvent evaporation, and the annealing time is at least required to allow the entire perovskite precursor liquid film 21 to be crystallized and converted into a perovskite solid film, which generally requires 8 to 20 minutes.

[0116] That is, in this embodiment, annealing can be performed in stages. The first stage is to use a specific light beam emitted by the light source 10 to perform radiation heating on the silicon substrate 20 for 20 to 60 seconds, so that the temperature of the silicon substrate 20 is maintained between 60° C. and 200° C. (for example, 150° C.). This is the initial stage of annealing (such as S110 in Figure 9). The main purpose is to nucleate at the buried bottom interface of the liquid film close to the silicon substrate to form tiny crystal nuclei. The second stage is to use a specific light beam emitted by the light source 10 to perform radiation heating on the silicon substrate 20 for 8 to 20 minutes, so that the temperature of the silicon substrate 20 is maintained between 60° C. and 200° C. (for example, 150° C.). This is the subsequent annealing stage of annealing (such as S120 in Figure 9). The main purpose is to accelerate the evaporation of the solvent in the liquid film, so that the tiny crystal nuclei continue to grow, and the overall performance is bottom-up crystallization to form a perovskite film.

[0117] In this embodiment, after the first stage of heating annealing is performed, the flow of the gas containing at least one perovskite solvent into the chamber 60 may be stopped (ie, the first switch 711 on the first pipe 71 is closed).

[0118] The second preset time is greater than the first preset time. For example, the first preset time may be 30 seconds, and the second preset time may be 10 minutes.

[0119] After the subsequent annealing stage is completed, the light source 10 and the vacuum valve (i.e., the second solenoid valve 741 mentioned above) are turned off, and then the second switch 721 on the second pipe 72 is opened to allow dry air to flow into the chamber 60. In this way, the pressure in the chamber 60 gradually returns to atmospheric pressure, and the silicon substrate 20 and the carrier 90 are taken out after the vacuum is released.

[0120] In other embodiments, the perovskite thin film annealing method provided by the present disclosure includes:

[0121] First, the chamber 60 is cooled through the cooling pipe 62 of the perovskite thin film annealing device; illustratively, the chamber 60 can be cooled to 18° C. (only for example).

[0122] Then, the silicon substrate 20 and the carrier plate 90 are placed in the chamber 60 , and the chamber 60 is evacuated to 0.1 Pa by the vacuum pump 80 .

[0123] Then, the first switch 711 on the first pipe 71 is opened, so that the chamber 60 is filled with a gas containing at least one perovskite solvent. In a specific implementation, the first switch 711 can be a gas mass flow controller (MFC). The carrier gas can be, for example, nitrogen, and the perovskite solvent can be DMF. Nitrogen is passed into the DMF solution bottle, and then the overflowed gas is collected above the liquid level of the DMF solution bottle to obtain a gas containing DMF, which is then filled into the chamber through the first pipe 71. In this step, the gas flow rate can be adjusted to 200 sccm by the gas mass flow controller, and the chamber vacuum is maintained at 1 Pa.

[0124] Next, light source 10 is turned on to radiate heat onto silicon substrate 20 using a specific light beam. For example, the temperature of silicon substrate 20 is controlled at approximately 150°C and maintained for approximately 30 seconds to complete the initial annealing phase. Annealing is performed for 30 seconds while maintaining the perovskite precursor liquid film 21 in a liquid state (i.e., with the upper surface wetted) to promote nucleation and crystallization of the perovskite from the bottom.

[0125] Then close the first switch 711 and maintain the temperature of the silicon substrate 20 at 150° C. for 10 minutes to complete the subsequent annealing stage. In this step, annealing is performed without introducing any gas or by introducing dry nitrogen or air to accelerate the evaporation of the solvent in the liquid film.

[0126] Finally, the light source 10 is turned off, the vacuum pump 80 is turned off, the second switch 721 on the second pipe 72 is turned on, the chamber 60 is restored to the atmosphere, and the silicon substrate 20 and the carrier 90 are taken out.

[0127] Of course, the above process steps are merely examples. In other embodiments, the step of introducing a gas containing at least one perovskite solvent and the initial annealing step can be omitted. In this case, the perovskite thin film annealing method can be implemented as follows: The chamber 60 can be cooled by cooling pipe 62 passing through the perovskite thin film annealing device. For example, the chamber 60 can be cooled to 23°C (for example only) to prevent the solvent from evaporating quickly before the liquid film is exposed to light, thereby drying out the film. The silicon substrate 20 and the carrier plate 90 are then placed in the chamber 60. The second switch 721 on the second pipe 72 is then opened to introduce nitrogen (or other inert gas or dry air) into the chamber 60. The first solenoid valve 731 is then opened to purge the chamber 60 (the purge time is approximately 30 seconds) until a nitrogen atmosphere is maintained in the chamber 60 (maintaining an inert atmosphere is primarily to prevent the perovskite precursor liquid film 21 from being affected by water and oxygen in the air in the original chamber). The light source 10 is then turned on, and the silicon substrate 20 is heated to 120°C and maintained for 10 minutes. Finally, the light source 10 is turned off, and the silicon substrate 20 and the carrier plate 90 are removed. Since the present disclosure transfers heat from the silicon substrate 20 to the perovskite precursor liquid film 21 from the bottom up, bottom-up crystallization can still be achieved.

[0128] The present disclosure also provides a solar cell comprising a perovskite film layer, wherein the perovskite film layer is made using the perovskite annealing device or perovskite annealing process provided by any of the above embodiments. The solar cell can be a single-junction or multi-junction cell, and the multi-junction cell can be a two-terminal, three-terminal, or four-terminal cell. Exemplarily, the solar cell is a perovskite single-junction cell, or a full perovskite tandem cell, or a crystalline silicon perovskite tandem cell, or a tandem cell of perovskite and other cells.

[0129] In addition, it should be noted that the perovskite thin film annealing method and the related processes mentioned in the above device embodiment can be referred to each other, and will not be explained again here.

[0130] The foregoing description is merely an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that the present disclosure is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure.

[0131] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations. Industrial Applicability

[0132] In summary, the present disclosure provides a perovskite thin film annealing device and annealing method, and a solar cell, which can use a silicon substrate as a heat source to heat and anneal a perovskite precursor liquid film, so that the perovskite can crystallize from the side close to the silicon substrate to the side away from the silicon substrate, thereby improving the crystallization quality of the perovskite precursor liquid film and improving the battery efficiency and stability.

Claims

1. A perovskite thin film annealing device, characterized in that: The method comprises a light source configured to emit a specific light beam for heating a silicon substrate of an annealed sample, wherein the annealed sample comprises a perovskite precursor liquid film formed on the silicon substrate. The silicon substrate is heated under the irradiation of the specific light beam and the perovskite precursor liquid film is heated so that the perovskite precursor liquid film crystallizes from a side close to the silicon substrate to a side away from the silicon substrate.

2. The perovskite thin film annealing device according to claim 1, characterized in that: The light source is located on the side of the silicon substrate coated with the perovskite precursor liquid film, and the wavelength of the specific light beam is between 850nm and 900nm; and / or, The light source is located on a side of the silicon substrate that is not coated with the perovskite precursor liquid film, and the wavelength of the specific light beam is between 400 nm and 900 nm.

3. The perovskite thin film annealing device according to any one of claims 1 to 2, characterized in that: The perovskite thin film annealing device further includes a fly-eye lens disposed between the light source and the silicon substrate, wherein the fly-eye lens is configured to homogenize and constrain the light beam emitted by the light source.

4. The perovskite thin film annealing device according to any one of claims 1 to 3, characterized in that: The perovskite thin film annealing device also includes a temperature sensor and a controller; the probe of the temperature sensor is arranged on the side of the silicon substrate away from the light source, and is configured to detect the temperature of the silicon substrate and send it to the controller; the controller is configured to control the output power of the light source according to the temperature of the silicon substrate.

5. The perovskite thin film annealing device according to any one of claims 1 to 4, characterized in that: Also includes: a chamber configured to accommodate the annealed sample, and a first conduit communicating with the chamber; The first pipe is configured to fill the chamber with a gas containing at least one perovskite solvent at the initial stage of annealing to keep the surface of the perovskite precursor liquid film wet; Optionally, a plurality of air outlet holes are further provided in an area of ​​the chamber wall facing the annealing sample, and the plurality of air outlet holes are connected to the first pipeline.

6. The perovskite thin film annealing device according to claim 5, characterized in that: A cooling channel is provided in the wall of the chamber and is configured to cool the chamber before annealing.

7. The perovskite thin film annealing device according to any one of claims 5 to 6, characterized in that: The first pipe is also provided with a first switch for controlling whether the first pipe is turned on. The first switch is configured to turn on the first pipe at the initial stage of annealing and turn off the first pipe in the subsequent annealing stage after the initial stage under the control of the controller.

8. The perovskite thin film annealing device according to any one of claims 5 to 7, characterized in that: Also includes: a second pipe having one end in communication with the chamber, and a second switch disposed on the second pipe; The second conduit is configured to fill nitrogen or dry air into the chamber in a subsequent annealing stage after the initial stage.

9. The perovskite thin film annealing device according to any one of claims 5 to 8, characterized in that: The perovskite thin film annealing device further includes: a third pipe having one end connected to the chamber and a first solenoid valve connected to the third pipe; the third pipe is configured to discharge the gas in the chamber.

10. The perovskite thin film annealing device according to any one of claims 5 to 9, characterized in that: The perovskite thin film annealing device also includes a fourth pipe, a vacuum pump and a second solenoid valve; one end of the fourth pipe is connected to the chamber and the other end is connected to the vacuum pump, and the second solenoid valve is connected to the fourth pipe; the vacuum pump is configured to vacuum the chamber through the fourth pipe.

11. The perovskite thin film annealing device according to any one of claims 1 to 4, characterized in that: Also includes: a first chamber configured to perform an initial annealing on the annealed sample, and a second chamber configured to perform a subsequent annealing on the annealed sample; The first chamber is provided with a first pipe in communication with the first chamber, and the first pipe is configured to fill the first chamber with a gas containing at least one perovskite solvent at the initial stage of annealing to keep the surface of the perovskite precursor liquid film wet; a cooling pipe is provided in the wall of the first chamber and is configured to cool the first chamber before the annealing; The second chamber is provided with a second pipe having one end connected to the second chamber; the second pipe is configured to fill the second chamber with a gas that does not contain a perovskite solvent in a subsequent annealing stage after the initial stage; the second chamber is also provided with a fourth pipe, one end of the fourth pipe is connected to the second chamber, and the other end is connected to a vacuum pump, and the vacuum pump is configured to evacuate the second chamber through the fourth pipe.

12. A method for annealing a perovskite film, characterized in that: include: A specific light beam is used to perform radiation heating on the annealed sample so that the silicon substrate of the annealed sample is heated before the perovskite precursor liquid film, so that the perovskite precursor liquid film crystallizes from a side close to the silicon substrate to a side away from the silicon substrate, wherein the perovskite precursor liquid film is formed on the silicon substrate.

13. The perovskite thin film annealing method according to claim 12, characterized in that: When the specific light beam irradiates the annealed sample from the side of the silicon substrate coated with the perovskite precursor liquid film, the wavelength of the specific light beam is between 850 nm and 900 nm; and / or, When the specific light beam irradiates the annealed sample from the side of the silicon substrate not coated with the perovskite precursor liquid film, the wavelength of the specific light beam is between 400 nm and 900 nm.

14. The perovskite thin film annealing method according to any one of claims 12 to 13, characterized in that: At the initial stage of annealing, a specific light beam is used to perform radiation heating on the annealed sample while keeping the surface of the perovskite precursor liquid film wet.

15. The perovskite thin film annealing method according to any one of claims 12 to 14, characterized in that: At the initial stage of annealing, a gas containing at least one perovskite solvent is filled into the chamber of the annealing device to keep the surface of the perovskite precursor liquid film wet; In the subsequent annealing stage after the initial stage, the filling of gas into the chamber is stopped, or the chamber is filled with gas that does not contain a perovskite solvent.

16. The perovskite thin film annealing method according to claim 15, characterized in that: Also includes: Before annealing and at the initial stage of annealing, the chamber is cooled by a cooling pipe arranged in the chamber wall of the annealing device, so as to keep the surface of the perovskite precursor liquid film wet at the initial stage of annealing.

17. The perovskite thin film annealing method according to any one of claims 15 to 16, characterized in that: In the initial stage, the annealing temperature is between 60° C. and 200° C., and the annealing time is between 20 and 60 seconds; In the subsequent annealing stage, the annealing temperature is between 60° C. and 200° C., and the annealing time is between 8 and 20 minutes.

18. A solar cell comprising a perovskite film layer, characterized in that: The perovskite film layer is manufactured using the perovskite annealing device described in any one of claims 1 to 11, or using the perovskite annealing process described in any one of claims 12 to 17.

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